Genes can define if you are a hard-worker or a lazy one

COLUMBIA, Mo. — New research from the University of Missouri suggests certain genetic traits may predispose people to being more or less motivated to do sport exercise. The importance of these finding stays with the plausible hypothesis that not only sport but other human accomplishments might be dependent on genetics. The researches repeated selection process through 10 generations and found that the tribe of hard-exercising rats chose to run 10 times more than the line of “lazy” rats. Both hard-working and lazy rats were produced by selective interbreeding of nominally identical rats. Thus the results suggest that within as little as 10 generations a sub-species of animal could be derived that would voluntarily "work" 10 times harder.

In biology, a subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more (including any that are extinct), never just one. Members of one subspecies differ morphologically or by different coding sequences of DNA from members of other subspecies of the species. Subspecies are defined in relation to species. Cryptic species are morphologically similar, but have differences in DNA or other factors. Organisms that belong to different subspecies of the same species are capable of interbreeding and producing fertile offspring, but they often do not interbreed in nature due to geographic isolation or other factors. The differences between subspecies are usually less distinct than the differences between species. The characteristics attributed to subspecies generally have evolved as a result of geographical distribution or isolation. Based on the new data, it is reasonable to further assume that geographic isolation of groups of animals of the same species could produces subspecies with as much as factor 10 ability to do a focused work or exercise.

Frank Booth, a professor in the MU College of Veterinary Medicine, along with his post-doctoral fellow Michael Roberts, were able to selectively breed rats that exhibited traits of either extreme activity or extreme laziness. They say these rats indicate that genetics could play a role in exercise motivation, even in humans. There is no obvious reason why the same genetics would not impact the ability of rats to search for food or do any other sort of creative work. The same type of genetic imprint should be true for humans. Thus this big discovery suggests that genetic factors could be of great importance in functioning of various human societies

The researches choose to focus their conclusions only on physical or sport activities, but future work would show if the efforts in other activities can also be programmed genetically. “We have shown that it is possible to be genetically predisposed to being lazy,” Booth said. “This could be an important step in identifying additional causes for obesity in humans, especially considering dramatic increases in childhood obesity in the United States. It would be very useful to know if a person is genetically predisposed to having a lack of motivation to exercise, because that could potentially make them more likely to grow obese.”

In their study published in the American Journal of Physiology: Regulatory, Integrative and Comparative Physiology on April 3, 2013, Roberts and Booth put rats in cages with running wheels and measured how much each rat willingly ran on their wheels during a six-day period. They then bred the top 26 runners with each other and bred the 26 rats that ran the least with each other. They repeated this process through 10 generations and found that the line of running rats chose to run 10 times more than the line of “lazy” rats.

Once the researchers created their “super runner” and “couch potato” rats subspecies, they studied the levels of mitochondria in muscle cells, compared body composition and conducted thorough genetic evaluations through RNA deep sequencing of each rat.

“While we found minor differences in the body composition and levels of mitochondria in muscle cells of the rats, the most important thing we identified were the genetic differences between the two lines of rats,” Roberts said. “Out of more than 17,000 different genes in one part of the brain, we identified 36 genes that may play a role in predisposition to physical activity motivation.”

Now that the researchers have identified these specific genes, they plan on continuing their research to explore the effects each gene has on motivation to exercise.

Frank Booth also is a professor in the Department of Physiology in the MU School of Medicine as well as a research investigator in the Dalton Cardiovascular Research Center at MU. This research also featured Kevin Wells, an assistant professor of genetics in the College of Agriculture, Food and Natural Resources Division of Animal Sciences.

As a result of years of excellence in providing systematic, periodic examinations of scholarly research and provoking discussion leading to new research activity, Frank Booth will be awarded the American Physiological Society (APS) 2013 Annual Reviews Award for Scientific Reviewing. The award recognizes an APS member who has written scientific reviews that have helped provide an enhanced understanding of the area of physiology reviewed.